| From: | "Daniel Verite" <daniel(at)manitou-mail(dot)org> |
|---|---|
| To: | "Jeff Davis" <pgsql(at)j-davis(dot)com> |
| Cc: | Peter Eisentraut <peter(at)eisentraut(dot)org>, Robert Haas <robertmhaas(at)gmail(dot)com>, Pgsql-Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Support LIKE with nondeterministic collations |
| Date: | 2024-08-01 19:55:55 |
| Message-ID: | 9364e6e6-9cc2-4eb1-91b1-dc4c780af597@manitou-mail.org |
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| Lists: | pgsql-hackers |
Jeff Davis wrote:
> > col LIKE 'smith%' collate "nd"
> >
> > is equivalent to:
> >
> > col >= 'smith' collate "nd" AND col < U&'smith\ffff' collate "nd"
>
> That logic seems to assume something about the collation. If you have a
> collation that orders strings by their sha256 hash, that would entirely
> break the connection between prefixes and ranges, and it wouldn't work.
Indeed I would not trust this trick to work outside of ICU collations.
Best regards,
--
Daniel Vérité
https://postgresql.verite.pro/
Twitter: @DanielVerite
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